Diamond drill bit



o. v. LINDQUlsT 2,40L087 DIAMOND DRILL BIT v Filed Nov. 8, 1945 ATTORNEY Patented May 28, ld

Donn f olaf v. Linaqms't, Larchmom, N.

J. K. Smit Sons, Inc., poration oi New York Application November-.8, 1945, Serial No. 627,326 v 6 Claims.

My invention is directed to an improvement in drill bits, particularly diamond drill bits adapted for drilling silicon and carbide grinding wheels, ceramics, etc. j

One of the objects of my invention is to provide a diamond drill bit which not only possesses obtained excellent results the ability to retain the diamonds and prevent their dislodgement, but is very highly abrasion resistant which is of importance and 1pecornes a valuable asset when drilling materials such as those above mentioned, for example.

Broadly speaking my invention provides a.

shell, tube or blank 2, to the end of which attach diamonds Il constituting the abrading and cutting elements of the bit.

In the manufacture of my improved bit I insert tube 2 on end in a graphite mold t. A graphite plug 8 is inserted into the tube, this plug bottomv ing on' the mold. The graphite plug is sufliciently long so as to extend above the end of the linlsned bn. Y

A layer of diamonds or diamond particles is then placed upon the upper end or" the tube 2 ard over and about this layer I apply a mixture l0 of powdered metals. Then another diamond layer is placed upon the metal powder and more metal powder upon this layer followed by still" another diamond layer, until aspmany layers or strata as may be desired have been placed in position. r

Pressure of around 1000 lbs. per square inch is then applied to the diamond and powdered metals mass by the plunger I2, after which I heat. preferably in an inert atmosphere to around 2000c F. for live or ten minutes, and before the mass has cooled pressure of the order mentioned above is again applied thereto.

The tool is then removed from the mold and allowed to cool down or it may be quenched, depending upon the characteristics desired-in the finished tool.

The powdered metals portion of the drill bit constitutes a matrix in which the diamonds are following parts by weight:

BIT

Y., assignor to New York, N. Y., a corembedded and retained. This matrix is oinew and novel composition. It is composed of a mlx` ture of manganese, carbon, iron and nickel boron.

It is to be understood that the relative quantities of these materials may be varied, but I have when employing the Manganese 11/2 Carbon 1% iron -..A 80 Nickel boron; 17

I and in the sintering process that the iron particles alloy with the manganese and carbon and hence are changed into manganese steel particles. y

The nickel boron has a lower melting point than the manganese steel particles, so that at the temperature used, say 2000 F. the nickel boron iows freely around all the manganese steel `particles welding them together and welding the lentire sintered metal mass to the steel blank 2. f

I find also that the matrix of my improved tool is exceptionally tough and abrasive-resistant adapting the same for thin walled shapes capable 'of withstanding the abuse to which my'tool is lsubjected in the drilling of such materials as coarse silicon and carbide grinding wheels.

What I claim is:

1. A diamond tool comprising a steel blank and a'diamond-impregnated matrix of manganese steel particles welded to each other and to the tool blank by nickel boron.

, 2. A diamond tool comprising a metal blank and a. diamond-impregnated matrix of sintered manganese steel particles welded to each other and to the tool lblank by nickel boron.

3.. In the making of diamond tools the method which comprises subjecting a pressed mass of manganese and carbon, iron and nickel boron particles and diamond particles to a temperature at which the manganese, carbon and iron are converted to particles of manganese steel welded together into a tough,` highly abrasive-resistant mass by the nickel boron.

4. In the making of diamond tools the method which comprises subjecting a mass of manganese,v carbon, iron and nickel boron particles and diamond particles to pressure, thereafter converting the manganese, carbon and iron particles to, par# Y ganese steel particles to each other with the nickel l A boron, by subjecting the pressed mass to a. temperature of around 2000 F.

5. In the making of diamond tools the method which comprises applying pressure to a mass comprising diamond particles and particles of manganese, carbon, iron and nickel boron in the following quantities by weight: I

Manganese 11/2 Carbon' 1% Iron 80 Nickel boron 17 and subjecting the pressed mass ta e. temperature of around i2000 F. to convert the manganese, carbon and iron to manganese steel particles and to cause the nickel boron to flow around the steel partlclesto weld the same to each other.

6. In the making of-diamond tools the method` which comprises applying pressure of theorder of- 1000 pounds per square inch to a mass comprisng diamond particles and' particles of mam-v ganese, carbonl iron and nickel boron, subjecting the pressed mass to a temperature of around 2000 F. for e length of time sumcient to convert the manganese, carbon and iron to manganese steel particles, and to cause the nickel boron to iiow around the steel particles to weld the same to each other, and while the mass is still at an elevated temperature again subjecting to a. pressure of the order of 1000 pounds per square inch.

oLoF V. uNDQUIsT'. 

